View Full Version : Filter capacity versus tank volume
Tesla_HV
05-08-2007, 11:56 AM
Is there a formula to calculate how much flow rate a properly-sized filtering system needs to have for a given volume?
J double R
05-08-2007, 11:59 AM
nope, it's variable depending on a lot of things other than tank volume.. ie.. bioload, type of fish, amount of plants, etc etc.. you'll find that most people try to have a flow rating of at least 10x their tank volume.
Tesla_HV
05-08-2007, 12:01 PM
nope, it's variable depending on a lot of things other than tank volume.. ie.. bioload, type of fish, amount of plants, etc etc.. you'll find that most people try to have a flow rating of at least 10x their tank volume.
per hour?
per hour?
Yep 10x the volume of the tank per hour, but it depends on the type of filter as well.
Tesla_HV
05-08-2007, 12:06 PM
10x per hour....wow!....that's a lot for a large outdoor pond. Mine is about 180 gallons and I have about 10 small to medium size comets in there. A few batches of Anacharis and Hornwort plus five hardy lily plants that have not sprouted leaves yet.
Yes i agree 10x is alot i do3 to 4x an hour gives bacteria time to work and even at that rate some of my plants are growing sideways
BIGgourami
05-17-2007, 9:21 PM
10x is ideal for filteration
but anywhwere from 2-5 is easy attainable for most purposes
IMO
12 Volt Man
05-17-2007, 9:21 PM
10x per hour is difficult to attain with anything but hang on tank filters though, which often have higher rated flow rates than canisters..
even the large canister for big tanks only run up to about 350 gallons per hour, so on a 90+ gallon tank, you are nowhere near 10x.
the catch is that with larger canisters you don't NEED to have as much flow because you have tons more media to compensate.
you can achieve 10x with multiple filters though, but its not really necessary.
even 4x per hour is plenty with proper tank management.
snickle
05-17-2007, 9:49 PM
I try for a 4x to 5x flow rate. My 10 has more, my 20 has that, my 90 needs more.
Mgamer20o0
05-18-2007, 12:25 AM
10x per hour is difficult to attain with anything but hang on tank filters though, which often have higher rated flow rates than canisters..
even the large canister for big tanks only run up to about 350 gallons per hour, so on a 90+ gallon tank, you are nowhere near 10x.
the catch is that with larger canisters you don't NEED to have as much flow because you have tons more media to compensate.
you can achieve 10x with multiple filters though, but its not really necessary.
even 4x per hour is plenty with proper tank management.
most large canister turn over rate is 350 gph with out media. once the media is in the turn over rate is lowered. i know the rena xp claims 187gph with media.
most people shoot for 5-10 turn over rate. it all depends on the tank.
there are filters for ponds that give high turn over rate.
PDX-PLT
05-18-2007, 1:43 AM
Another thing to keep in mind is that filter manufacturers are engaging in quite a bit of "specsmanship" when it comes to GPH ratings. As was mentioned, alot of time the quote number is the "raw" pump number, which assumes no restrictions: no media, zero head height, etc. In other words, nothing like the real world conditions. But since GPH is just about the only number you can advertise for a filter, they try to make it as big as possible.
Having a big GPH number and a relatively small volume of media doesn'y make alot of sense, either.